Abstract

We demonstrate the use of a very simple, compact, and versatile method, based on the hollow-fiber compression technique, to shorten the temporal length of visible laser pulses of 100–300fs to pulse durations shorter than ≈50fs. In particular, 200fs, frequency-doubled, Nd:glass laser pulses (527nm) were spectrally broadened to final bandwidths as large as 25nm by nonlinear propagation through an Ar-filled hollow fiber. A compact, dispersive, prism-pair compressor was then used to produce as short as 40fs, 150μJ pulses. A very satisfactory agreement between numerical simulations and measurements is found.

Figures (3)

Measured autocorrelation pattern of the (a) initial laser pulse, with (b) autocorrelation profile of the spatially integrated pattern. Measured autocorrelation pattern of the (c) compressed laser pulse, with (d) autocorrelation profiles of the overall spatially integrated pattern, and (e) of the pattern integrated over the evidenced spatial window, which is the wavefront portion where the pulse reaches its highest intensity. Reported measurements are the result of a 10 shot average. The curves in (d) and (e) refer to Gaussian best fits to autocorrelation profiles.

(a) Measured (bullets) and simulated (solid curve) power spectrum of the broadened pulse, with the relative simulated spectral phase (dashed line), in correspondence of the autocorrelation trace reported in Fig. 2. (b) Retrieved pulse intensity of the compressed pulse as a function of time (solid curve) and corresponding field phase (dashed curve).